1. Field of the Invention
The present invention relates to a brain cooling device.
2. Description of the Related Art
In organisms such as a human body, an amount of oxygen supplied to the brain becomes insufficient due to a failure of the respiratory function or the circulatory function like in a cardiac arrest (hereinafter, referred to as the cardiac arrest state), and this insufficient oxygen supply is known to cause a death of brain cells, so-called ischemic neuron damage.
Meanwhile, treatment for resuscitation from the cardiac arrest state, such as artificial respiration, is practiced on an organism in the cardiac arrest state. However, even in a case where the organism in the cardiac arrest state is resuscitated by this treatment, aftereffects are highly likely to occur in the brain due to the ischemic neuron damage.
Under these circumstances, a treatment to cool the brain by lowering the body temperature of an organism in the cardiac arrest state with the aim of suppressing the occurrence of the ischemic neuron damage, known as the hypothermic treatment, has been proposed in recent years.
The hypothermic treatment is more effective when it is practiced sooner upon the occurrence of ischemia, and the treatment effect decreases sharply with an elapse of time.
Adopted in the hypothermic treatment are a method for lowering the body temperature of an organism by wrapping the whole body with a blanket or the like inside of which a cooling fluid is circulating, and a method for directly cooling the head by covering the head of the organism with a covering material inside of which a cooling fluid is circulating as is disclosed, for example, in JP-A-2000-60890.
In each case where the body temperature is lowered using the blanket or the covering material, however, the body is cooled from the surface of the body. Hence, not only it takes a time to lower the temperature of the brain, but also it is difficult to cool the brain sufficiently to the subcortical tissue.
In a case where the organism is resuscitated from the cardiac arrest state while the whole body is cooled with the blanket, there is a risk of inducing irregular heartbeats accompanying a drop in temperature of the whole body. Accordingly, careful attention should be paid to the cooling timing of the organism with the use of this blanket.